Speaking of Gov. Spitzer, we wonder: Just how low can his approval ratings go? Lower than in the new Siena College Research Institute poll?

Only 36 percent of New York voters have a favorable opinion of Spitzer, according to the survey; 51 percent have an unfavorable view.

His job-performance rating is even worse: just 27 percent positive, and a stunning 70 percent negative. (Ouch!)

With each passing month, the numbers continue to plummet: The percentage of voters who view Spitzer favorably is down five points from last month, 18 points from the month before and a total of 31 points since May.

You’d think Spitzer would get the message – but there’s no sign of that so far.

Voters began souring on the governor soon after Post State Editor Fredric U. Dicker broke news in July of Team Spitzer’s Dirty Tricks campaign to smear Senate Majority Leader Joe Bruno.

Spitzer could’ve stopped the bleeding right there – by showing that he wasn’t personally involved in the scandal. That would’ve meant cooperating with authorities probing the affair and, most likely, testifying about it publicly.

Instead, he stonewalled at every turn.

His aides fought nearly every request for papers and sworn statements.

Spitzer himself has used one excuse after another for not telling his side of the story publicly and under oath.

Just last Friday, he blamed Public Integrity Commission rules for his refusal to disclose any testimony he may give that body.

Yet experts say that no law bars his release of a transcript.

Apparently, Spitzer doesn’t care that 70 percent of New Yorkers insist that he come clean. (Leaving folks to wonder just what exactly it is that he’s hiding.)

Nor are his ratings rebounding despite his decision to scrap his driver’s-licenses-for-illegal-aliens idea. That plan cost him big-time in the polls; now that it’s history, you’d think the ratings would bounce back – but no such luck.

That they fell yet again suggests that voters are growing ever-angrier with Spitzer’s failure to tell the truth about Dirty Tricks. They’ll keep falling, too, until that whole sordid affair is unveiled.

Meantime, he’ll have no reservoir of public support or good will to draw on as he pushes his political agenda. He faces months, if not years, of paralysis.

Spitzer may be tempted to pander to this group or that to garner support. Never mind the damage that could do New York; it won’t even work for him.

Actually, the driver’s-license fiasco appears to have been born of just such a temptation; again, it backfired miserably. As will, we suspect, his apparent catering to soft-on-crime liberals by loosening parole restrictions on violent felons. (See above.)

No, there’s only one hope for the gov: Tell the truth. Publicly. Under oath.